In the mass production of snack products, such as potato chips and corn chips, curved configurations are either produced naturally by the frying process or may be imparted mechanically by molding or forming machines. The curved shape is considered a desirable feature both from a visual aspect and from the fact that it facilitates use of the snack with dips because the curved shape makes it easier to collect and maintain the dip on the surface of the snack. Furthermore, the curved shape of the snack results in a lower bulk density in the packaging, giving the packaged product a pleasantly filled appearance. However, frying generally results in a high fat content product, which is generally bubbled or blistered and not amenable to stacking or packaging in a straight stack. Also, frying is not compatible with obtaining a snack product which has a sweet, cookie taste. Moreover, the forming machines employed by potato chip and corn chip manufacturers are generally complex, mechanically intensive, and require significant manufacturing line spaced.
For example, in the manufacture of corn chips, the curled shape present in corn chips may be obtained by the use of a pressurized extrusion process. The curl forms as the product exits the extrusion head. The use of extrusion equipment, however, limits the type of flours which may be used to make up the dough since some, such as wheat flours, tend to burn under the temperatures found in an extrusion chamber. Furthermore, the extruded product may need to be subjected to deep fat frying.
U.S. Pat. No. 3,576,647 to Liepa discloses that in making potato chips, slices of raw potatoes are deep fat fried to a crisp state. The chips so prepared have a random surface curvature which usually takes on a saddle-like appearance. However, frying is the only acceptable means of producing the curve shaped product described and the chips are prepared not from doughs but whole slices of potato.
The use of mechanical means to impart a curved shape to flat snack products is disclosed in U.S. Pat. No. Re. 31,819 to Weiss et al. In the Weiss et al process and apparatus fabricated potato chips are prepared from a flat dough ribbon, in which if a curved shape is desired, the flat dough ribbon is molded between concave and convex surfaces during the frying step to produce the desired shape.
U.S. Pat. Nos. 3,576,647 and 3,626,466 each to Liepa teach a method for preparing a saddle shaped fabricated potato chip by sheeting and cutting the desired shape from the dough sheet. Each dough piece is then held between two similarly configured molds as the dough piece is conveyed through the deep fat frying step to ensure that the piece maintains its deformed shape.
U.S. Patent Publication No. 2002/0132029 A1 to Teras et al discloses the production of an ergonomic snack piece having a dip containment configuration by frying or baking dough which is constrained between belts or molds.
U.S. Patent Publication No. 2002/10034571 A1 to Zimmerman et al discloses the production of a tortilla chip having a dip containment configuration by frying or baking dough which is constrained between belts or molds.
As disclosed in U.S. Pat. No. 5,392,698 to Sprecher et al, one means for imparting a concave shape to an oven baked cracker-type snack product is to replace the normal flat band of a commercial oven with a specially fabricated band that has spaced ridges affixed to the band such that when the dough sheet is layed onto it, gravity pulls the unsupported middle of the dough sheet down resulting in a desirable concave shape. This is not a commercially desirable method since it requires a specially fabricated oven band which would have to be replaced with a flat band whenever the manufacturer wished to make other products without a curved shape. The manufacturer would end up with one oven dedicated to production of concave shape baked products, thus limiting production flexibility. Furthermore the concave shape is limited to one fixed angle since the ridges are not adjustable.
Generally it is also known in the art that a slight curvature can be imparted to a dough sheet being subjected to oven baking by varying the heat applied in the top and bottom zone of the band oven. For example, in manufacturing a thin wheat type cracker by applying greater heat to the dough sheet in the top zone and less heat in the bottom zone, the middle portion of the product will lift off the band to give a very slight convex shape. However the curvature which may be imparted to the product using this technique is slight, certainly less than 10 degrees. Furthermore the product produced tends to be non-uniform since it is difficult to control the amount of curvature which is imparted to the product using this baking method.
U.S. Pat. No. 4,844,919 discloses the production of a concave shaped baked snack product which is coated with a fused flavored particulate topping and the product can be made on existing, in-place commercial manufacturing equipment. The topping composition is made from a film-forming food starch and flavors and is applied to a sheeted dough prior to baking. During baking the topping composition becomes fused to the expanding dough base causing the edges of the dough sheet to lift up resulting in a desirable concave shaped coated snack product.
U.S. Pat. No. 6,277,425 B1 to Nash et al discloses the use of an air knife to cool and dry extrudate strands before cutting. The product produced by Nash et al may be in the shape of a tube.
The present invention provides a method and apparatus for forming baked, wheat-based wave chip products, such as cookie wave chips, without the use of complex, mechanically intensive forming machines. High line throughputs may be maintained without the need for diverting long manufacturing line space to chip curving operations, and without the need for curling compositions which are topically applied before baking. In accordance with the present invention, a curved or wave configuration may be imparted to baked products after baking. Various degrees of curvature may be achieved without the need for extensive modifications of existing manufacturing equipment which is employed to produce flat chip products, crackers, or cookies.